ORIGINAL PAPER Differential recombination dynamics within the MHC of macaque species

Abstract A panel of 15 carefully selected microsatellites (short tandem repeats, STRs) has allowed us to study segre-gation and haplotype stability in variousmacaque species. The STRs span the major histocompatibility complex (MHC) re-gion and map in more detail from the centromeric part of the Mhc-A to the DR region. Two large panels of Indian rhesus and Indonesian/Indochinese cynomolgusmacaques have been subjected to pedigree analysis, allowing the definition of 161 and 36 different haplotypes and the physical mapping of 10 and 5 recombination sites, respectively. Although most re-combination sites within the studied section of the Indian rhesus monkey MHC are situated between the Mhc-A and Mhc-B regions, the resulting recombination rate for this geno-mic segment is low and similar to that in humans. In contrast, in Indonesian/Indochinese macaques, two recombination sites, which appear to be absent in rhesus macaques, map between the class III and II regions. As a result, the mean recombination frequency of the core MHC,Mhc-A to class II, is higher in Indonesian/Indochinese cynomolgus than in Indi-an rhesus macaques, but as such is comparable to that in humans. The present communication demonstrates that the dynamics of recombination ‘hot/cold spots ’ in the MHC, as well as their frequencies, may differ substantially between highly related macaque species